不同水稻基因型地上部钾素累积和转运规律的研究（英文）

经水培苗期筛选后选用对低钾胁迫抗性不同的 9种水稻基因型进行田间试验 ,结果表明 ,低钾胁迫减少水稻体内钾的累积量 ,增加体内钾的运转速率。不同钾处理间水稻地上部钾素累积量和同一处理内不同水稻基因型间吸钾能力在生育前期差异均较大 ,后期则相对较小。水稻体内钾累积与运转能力的基因型差异非常显著。与钾低效基因型相比 ,钾高效基因型低钾胁迫下苗期地上部钾素累积量较大 ,孕穗期上位叶和下位叶中钾含量均相对较高 ,上位叶、下位叶间钾含量的差异也较大。     

不同水稻基因型地上部钾素累积和转运规律的研究

 经水培苗期筛选后选用对低钾胁迫抗性不同的9种水稻基因型进行田间试验，结果表明, 低钾胁迫减少水稻体内钾的累积量，增加体内钾的运转速率。不同钾处理间水稻地上部钾素累积量和同一处理内不同水稻基因型间吸钾能力在生育前期差异均较大，后期则相对较小。水稻体内钾累积与运转能力的基因型差异非常显著。与钾低效基因型相比，钾高效基因型低钾胁迫下苗期地上部钾素累积量较大，孕穗期上位叶和下位叶中钾含量均相对较高，上位叶、下位叶间钾含量的差异也较大。     

耐低钾基因型水稻成熟期籽粒淀粉与蛋白质含量变化

以2个耐低钾基因型水稻N18,N19和1个低钾敏感型水稻N27为材料,在缺钾条件下,分析耐低钾基因型水稻籽粒在成熟期淀粉含量、蛋白质含量的变化。结果表明：在不施钾肥即缺钾条件下,耐低钾基因型水稻籽粒中总淀粉含量较低钾敏感型的略有增加,且直链淀粉含量占总淀粉含量的比例低于钾敏感型;耐低钾基因型水稻籽粒中可溶性蛋白质含量也较低钾敏感型的高,但是钾元素的含量差异并不明显。     

聚乙二醇模拟干旱对耐低钾水稻幼苗光合特性的影响

以早籼品种瑰宝8号及其变异后代耐低钾水稻为材料,用20%PEG6000模拟干旱,对幼苗光合特性进行了研究,并对测定指标进行相关性分析。模拟干旱胁迫下,耐低钾水稻幼苗具有相对较高的钾含量、钾素利用效率、生物量、水势、光合速率、气孔导度和胞间CO2浓度。相关分析表明,水稻幼苗钾含量和钾素利用效率与生物量、光合速率、气孔导度、胞间CO2浓度和水势呈显著正相关。     

低钾胁迫对耐低钾基因型杂交水稻呼吸代谢的影响

低钾胁迫对耐低钾基因型杂交水稻呼吸代谢的影响沈伟其,陈建荣（浙江农村技术师范专科学校,宁波３１５１０１）关键词：杂交水稻;低钾胁迫;呼吸代谢ＥｆｆｅｃｔｏｆＰｏｔａｓｓｉｕｍＤｅｆｉｃｉｅｎｔＳｔｒｅｓｓｏｎＲｅｓｐｉｒａｔｏｒｙＭｅｔａｂｏｌｉｓｍ...     

水分胁迫对麦芽品质影响的基因型差异分析

大麦在开花后受到水分胁迫时,籽粒质量会降低而蛋白质含量则会增加,同时麦芽品质也大幅下降。然而,在不同的大麦基因型中,水分胁迫的负面影响差别很大。本研究采用不同水分胁迫耐受性的西藏野生大麦品种2个和栽培品种2个作为研究材料,分析了干旱条件下灌浆期籽粒代谢剖面的基因型差异。本研究中总共鉴定到71种不同积累的代谢物,包括有机酸、氨基酸/胺和糖/糖醇。所有基因型材料的代谢物相对含量均受水分胁迫的显著影响,且野生型和栽培型之间差异明显。对代谢物的主成分分析表明,西藏野生大麦XZ147对水分胁迫具有独特的响应方式。当受到水分胁迫时,野生大麦XZ147是4个基因型中籽粒β-淀粉酶活性升高最多的,这很可能是由于其较高的赖氨酸含量,较低的吲哚-3-乙酸(IAA)生物合成,更稳定的过氧化氢平衡,以及上调的BMY1基因表达。另一方面,干旱胁迫下野生大麦XZ147籽粒β-葡聚糖含量下降量超过其他基因型,这可能是由于其具有较高的灌浆速率和上调的β-葡聚糖合酶基因GSL7表达。这些结果表明,XZ147在大麦育种中具有很大的潜力,可以提高大麦的耐干旱胁迫能力。     

玉米苗期耐低钾基因型筛选方法研究

通过水培实验及低钾土壤的盆栽实验,研究了不同供钾水平对玉米苗期吸钾量和钾利用指数的影响及筛选耐低钾玉米基因型的最佳指标、适宜生育时期及钾浓度。结果表明,水培实验的筛选指标为钾利用指数优于吸钾量,筛选的适宜生育时期为6叶期,钾浓度为0.1mmol/L。经筛选初步确认吉单27为较耐低钾胁迫的基因型,先玉335在低钾胁迫条件下为相对敏感基因型。     

低磷胁迫下不同基因型水稻阶段性磷营养特征

采用盆栽试验研究了低磷胁迫条件下不同磷效率基因型水稻在分蘖期、孕穗期和成熟期的磷营养特征。在分蘖期,耐低磷基因型水稻吸磷量无论在何种磷处理条件下均显著高于低磷敏感基因型,低磷胁迫时,除99112T外其他耐低磷基因型水稻的磷利用效率也显著高于低磷敏感基因型;到孕穗期,耐低磷基因型水稻在低磷胁迫时仍具有较高的吸磷量,但是磷利用效率与低磷敏感基因型相比却没有明显差异;至成熟期,耐低磷基因型水稻的磷效率的贡献因子依次为：磷利用效率、吸收效率和转运效率。较低的吸磷量是99012S（低磷敏感基因型）在不同生育时期磷效率低下的主因,在生育前期磷吸收和利用效率低下及后期磷利用效率低下是另一个低磷敏感基因型99056S磷效率低下的主要原因。低磷胁迫还滞后了低磷敏感基因型的磷吸收,并随着低磷胁迫的加剧而增强。     

不同锌效率基因型水稻籽粒中矿质元素的原位微区分布研究

 采用同步辐射（SRXRF）结合ICP MS研究了足Zn条件下不同锌效率水稻籽粒中Zn及其他矿质元素的微区分布特征。结果表明SRXRF技术可高效分析水稻籽粒锌等矿质元素的微区分布特征。水稻籽粒中K和Ca元素的分布特征与其余4种元素相关不显著,而Zn、Fe、Cu、Mn元素的含量分布相互间则显著相关;水稻籽粒中K含量最高,移动性也最强,精米中K含量可达颖壳的52.6%~90.6%,而Ca在颖壳中含量最高。其余矿质元素含量最高值均出现在糊粉层;Zn、Fe等元素主要集中在水稻籽粒的胚及糊粉层等外层功能组织,在胚乳中由外向里呈递减趋势。此外,锌高效基因型IR8192在水稻籽粒各部位的Zn含量均低于锌低效基因型二九丰。可见,与锌低效品种相比,锌高效品种仅在低Zn水平下表现出更高的锌吸能力及利用效率,在足Zn条件下并无籽粒富锌特征。     

水稻灌浆期高温对天冬氨酸代谢酶活性及其家族氨基酸含量的影响

 选用粳稻越光和籼稻IR72为材料,研究了灌浆期高温对水稻籽粒中天冬氨酸转氨酶（AAT）、天冬氨酸激酶（AK）活性以及稻米蛋白质组分与天冬氨酸族氨基酸组分含量的影响。结果表明,水稻灌浆期高温下籽粒中AAT和AK活性、天冬氨酸、赖氨酸、苏氨酸、蛋氨酸和异亮氨酸相对含量均显著提高,籽粒中AAT和AK活性与天冬氨酸家族总氨基酸含量分别呈显著和极显著正相关,说明水稻籽粒中AAT和AK对于高温下稻米天冬氨酸家族氨基酸含量的提高具有重要作用。高温有利于稻米中蛋白质组分与天冬氨酸族氨基酸组分相对含量的提高,有利于单粒稻米中谷蛋白与天冬氨酸家族氨基酸组分的积累以及粗蛋白中部分氨基酸比例的改善,但高温降低了每穗稻米中蛋白质组分与部分氨基酸组分的含量。     

Variations in Concentration and Distribution of Health-Related Elements Affected by Environmental and Genotypic Differences in Rice Grains

Malnutrition is one of the major problems inmost of the developing countries, especially amongwomen, infants and children. Biofortification is a verynew strategy to enhance the bioavailability ofmicronutrients in staple food by using advancedbreeding meth…     

Variation in rice quality of different cultivars and grain positions as affected by water management

A field experiment was conducted to study the effect of cultivar and grain position on rice quality under different water management treatments. Water treatments significantly affected all quality traits in the study, except alkali digestibility (AD). There were significant interactions of water treatment by grain position and genotype for brown rice rate (BRR), chalky grain rate (CGR) and amylose content (AC), and interactions of grain position by water treatment and cultivar for head milled rice rate (HMRR). The interaction of water treatment by genotype for protein content (PC) was also significant. Of all variance components, water treatment ranked the highest for PC. Similarly grain position was ranked the highest for AC, BRR, CGR and HMRR. In comparison with wet cultivation, plastic-film mulched cultivation had significantly lower BRR, HMRR, CGR and higher PC. There were marked differences in milled quality, appearance and AD among differently positioned grains within a spike. For appearance and PC, the difference between plastic-film mulched cultivation and wet cultivation was greater for upland rice than paddy rice. For milled and cooking–eating quality, the difference between plastic-film mulched cultivation and wet cultivation was greater for the good quality paddy rice than the upland rice and the poor quality paddy rice. In plastic-film mulched cultivation, top grains showed lower milled quality and PC. While in wet cultivation, the opposite result was seen. With the decrease in soil water content, BRR and appearance showed increased and decreased differences among grains within a spike, respectively. The results indicate the possibility of improving rice quality by use of better water management and suitable cultivars.     

供锌水平对水稻生长和锌积累和分配的影响

通过对3个不同水稻品种（碧玉早糯、26715和浙农921）5个供锌水平（0.0、0.5、2.0、8.0、32.0 μmol/L ZnSO[sub]4[/sub]）处理的水培试验,研究供锌水平对水稻生长和锌积累的影响。结果表明,水稻地上部锌含量随供锌水平的提高而提高,不同的供试品种在不同的生育期地上部锌含量的变化趋势存在差别。不同的供试品种之间籽粒锌的积累差异极显著,精米中的锌含量随供锌水平的提高而提高;在8.0、32.0 μmol/L Zn水平下,籽粒锌含量差异不大,颖壳锌含量则随供锌水平的提高而提高;在≤8.0 μmol/L时,精米锌含量比颖壳高,而在高锌水平（32.0 μmol/L）下,颖壳的锌含量比精米高。     

Comparative Protein Digestibility in Growing Rats of Cooked Rice and Protein Properties of Indica and Japonica Milled Rices

College,Laguna, Philippines.Received 1 ABSTRACT Eight indica and japonica milled rices with low amylose content and low starch gelatinisation temperature were analysed for cooked rice energy and N balance in growing rats and for protein properties. Digestible energy values were similar. Japonica rices Koshihikari and Sasanishiki had higher true digestibility (TD) and net protein utilisation in rats than indica rices IR24 and PR23383-15. Similar results were obtained from in vitro proteolysis. High TD of cooked rices was not significantly correlated with low prolamin content in raw rice and with low waxy gene product (protein bound to starch granule) but was significantly correlated with low cysteine content in protein and with low denatured prolamin content in cooked rice. In two pairs of cooked waxy milled rices, which are devoid of waxy gene product, japonica rice still tended to show higher rat TD and in vitro protein digestibility than indica rice, consistent with lower cysteine content in japonica protein.     

Protein and energy utilization of rice milling fractions by rats

Brown rice (variety IR32), bran, and polish had higher protein content and lysine content in protein than milled rice. Nitrogen balance in growing rats showed that brown rice had lower true digestibility, but similar biological value and NPU as milled rice. Undermilled rice had similar true digestibility, but higher biological value and NPU than milled rice. Bran and polish had lower true digestibility, but higher biological value than brown and milled rice, but polish had higher NPU than bran and the three other milling fractions. The percentage of digestible energy in the rats was lowest for bran.     

Effect of treatment on composition and protein and energy utilization of rice and mung bean by rats

Yellow rice derived from stack-burned unthreshed grains had lower lysine content than white milled rice. Stack burning did not affect energy digestibility in growing rats but decreased true nitrogen digestibility and net protein utilization (NPU). Increasing parboiling time from 20 to 60 min had no adverse effect on energy and protein utilization of parboiled milled rice. Defatting of rice bran-polish with petroleum ether at 50°C had no effect on protein utilization but decreased energy content and utilization. Mechanical dehulling of mung bean (Vigna radiata [L.] Wilczek) reduced fiber content, increased energy and protein digestibility but decreased biological value (BV) and NPU. Toasting and winnowing the bean reduced lysine content, improved digestible energy but decreased BV and NPU. Cooking the bean preparations improved the biological value only in mechanically dehulled bean with resultant higher NPU than that of whole bean.     

烯效唑对水稻氮代谢及稻米蛋白质含量的影响

以杂交稻组合汕优63为材料,探讨了烯效唑处理对水稻开花后剑叶和籽粒氮代谢、稻米蛋白质含量及产量的影响。结果表明,烯效唑处理后,籽粒灌浆前、中期剑叶内可溶性蛋白质含量提高,而成熟期其含量与对照基本相同,甚至略低于对照;烯效唑提高了强、弱势粒中谷氨酰胺合成酶活性以及强势粒发育前期的非蛋白氮含量,并促进其向蛋白氮的转化,使成熟期非蛋白氮含量低于对照,而各时期蛋白氮含量均高于对照,成熟期强、弱势粒中蛋白氮含量和单粒蛋白氮绝对积累量均得以提高;烯效唑提高了稻米内蛋白质含量和蛋白质产量,浸种和喷施处理蛋白质含量平均分别比对照高7.2%和8.3%,蛋白质产量平均分别比对照高13.1%和13.4%。     

Effects of Uniconazole on Nitrogen Metabolism and Grain Protein Content of Rice

The effects of uniconazole by soaking seeds and spraying leaves at booting stage with different concentrations （0, 20 and 40 mg/kg） on the nitrogen metabolism of flag leaf and grains after flowering, and rice grain protein content and yield were studied with hybrid rice combination Shanyou 63. Under uniconazole treatment, the soluble protein content in flag leaf was increased in early and middle period of grain filling, but this content was nearly the same as or even lower than that of control at maturity; Glutamine synthetase activity in superior and inferior grains and non-protein nitrogen content in superior grains at early stage of grain development were promoted, and moreover, the transforming speed from non-protein nitrogen to protein nitrogen was accelerated; Non-protein nitrogen content was lower than that of control at maturity, but protein nitrogen content at each stage was higher than those of control; Protein nitrogen content in superior and inferior grains and protein nitrogen absolutely accumulative content in a grain both were enhanced and protein content and yield in rice grain were raised. The application of uniconazole by soaking seeds and spraying leaves raised crude protein content by an average of 7.2% and 8.3%, and protein yield by an average of 13.1% and 13.4%, respectively.     

稻田综合种养对长江中下游地区水稻产量和稻米品质影响的文献研究

基于已发表的文献数据,综述了长江中下游地区不同稻田综合种养模式对水稻产量形成和稻米品质的影响,并探讨其影响机理。41%的样本量数据表明,稻田综合种养的水稻产量高于水稻单作,而59%的样本量呈相反趋势;稻田综合种养的水稻穂数和穗粒数普遍减少,而结实率和千粒重增加。在长江中下游地区,相比于水稻单作,稻田综合种养稻米的加工、外观、蒸煮和食味品质在一定程度上得到改善。其中,糙米率、精米率和整精米率极显著提高0.72%～2.74%,胶稠度增加2.11%,垩白粒率、垩白度、直链淀粉含量和稻米蛋白质含量则分别下降13.78%、11.76%、3.01%和6.67%。